Apple's attack on Microsoft's Windows operating system took a viral turn on Tuesday, when the company warned that a third-party manufacturer for its iPod devices shipped a Windows virus with the popular music and video players.

The virus has been identified as the Rjump or Rajump worm by antivirus software makers and as RavMonE virus by Apple. Incidents of the virus infecting iPod owners occurred as early as September 22, according to comments on Apple's support forum.

Apple warned users about the virus-infected iPods on Tuesday, but did not apologize in its statement, which instead took a pot shot at Microsoft's operating system.

"As you might imagine, we are upset at Windows for not being more hardy against such viruses, and even more upset with ourselves for not catching it," the company stated.

The company said in its statement that less than 1 percent of the iPod's shipped after September 12 carry the virus.

The incident comes after McDonald's shipped 10,000 MP3 players in Japan with the QQPass password-stealing Trojan horse program. Several companies, including Microsoft and a hacking group, have inadvertantly shipped CDs with Trojan horses or viruses. Music giant Sony BMG also shipped more than 50 music titles on CDs with a draconian copy-protection system that qualified as malicious software.

Apple recommended that any person that buys a new iPod scan the device, and other mass-storage devices, for viruses.